Has anyone found any leaks (retail listings, code, etc) relating to any new packs?

The linked post is for a voice editor position -- it looks like a tech position, not a performance one. It could mean they're adding singing in depth or bands (there's nothing about instruments in there) or it could means they're short a voice editor, and they understand that Simlish is a challenge to make sound natural so they need someone who is very good at voice recording/editing.

While I'm hoping for the former, this is definitely a "not enough info" situation.